T-Tec Thermochron ® iButton dataloggers

iButton Specs
User Manual

iButton temperature data loggers

This surprising data logger looks exactly like a small battery but has the features of a larger datalogger. The price is on the level with disposable chart recorders, however, the Thermochron ® iButton has an expected lifetime of up to 8 years. It is water resistant and accurate to ±1 °C. To run the system you need a Thermochron ® interface, any number of Thermochrons ® and software.

Available Features

  • Water resistant
  • Meets UL#913 for intrinsically safe apparatus, approved under entity concept for use in Class I, Division 1, Group A

    ,B,Cand D Locations (application pending)

  • Intervals:

    Maybeset from 1 second to 4.5 hours, depending on the model.

  • Two-alarmpoints (max and min) may be set in software when starting the logger. Alarm status and time in alarm are shown when querying the logger from the computer.

This data logger has all the features of a larger temperature datalogger, but is the size of a small coin cell battery. These dataloggers are inexpensive, with a lifetime of 5-7 years. iButton dataloggers are water resistant and accurate to ±1 °C between -30 to + 70 °C.

Temperature Technology has expanded the T-TEC datalogger software to also operate the iButtons. A starter kit, complete with software, iButton-specific serial interface or USB adaptor and one Thermochron data logger, is available.

Model number Temperature Range Memory
DS1921G -30 + 70 °C 2,048
DS1921H +15 + 46 °C 2,048
DS1921Z -5 + 26 °C 2,048
DS1922E +15 +140 C 4,096 or 8,192*
DS1922L -30 +70 C 4,096 or 8,192*
DS1922T 0 + 125 C 4,096 or 8,192*
DS1923 -20 +85 C, 0 – 100%RH 2,048 or 4,096*

*Depending on the resolution

iButton Specs

Further technical specifications for iButtons

iButtons Data Logger Technical Specifications

Casing Polycarbonate, watertight to IP68 Humidity loggers splash proof from top
Size 65 × 31 × 106 mm
Weight 115 g
Ambient -40 + 85 °C
Battery 1 × ½AA, 3.6V
T-TEC 6: Expected battery life: 3-4 years
T-TEC 7: Expected battery life: 2 years, Low battery warning on display
Sensor (see sensor specifications) Temperature: Precision Thermistor or Pt100
Humidity: capacitive precision
Memory E model: 12,000 to 25,000 sets of measurements
C model: 10,600 sets each sensor
F model: 10,600 sets each sensor (21,200 if only one)
A & P: 20,000 to 60,000 sets of measurements
Interface Special interface cable to the serial port and/or special interface cable to USB Port
Security ID Permanent serial number
Warranty 1 Year (not incl. sensor)
Resolution Temperature: Better than 0.1 °C (see sensor specifications)
Humidity: Better than 0.1%RH

Special Alarm functions

T-TEC 6: Audio alarms, T-TEC 7 visual alarms

When starting the logging, one or two alarms may be set as minimum and/or maximum alarms. A period of grace may be set in minutes. Alarms can be programmed to reset themselves once a day at a chosen time. Type C loggers (For temperature and Humidity) have alarm functions for temperature only.

Special Relay Output

Some types may be supplied with optional relay output. Change-over relay, all three contacts available. Contacts: Gold clad silver contacts. Nominal switching capacity (Resistive load) 1A/30V DC, 0.5A 125V AC

Thermochron™ data logger specifications

Casing Stainless Steel, Polypropylene seal
Size 17.35mm diameter 5.9mm height
Weight 3.2 g
Ambient -40 to 85 °C. Should not be exposed to temperatures in excess of 70 °C for a prolonged time.
Battery Built-in: Non-replaceable
Estimated lifetime: 5-7 years, depending on:

  • ambient temperature
  • number logs were taken
  • resolution (DS1922 and DS1923)
  • Logging interval (DS1922 and DS1923)
Sensor Built-in, semiconductor
Memory DS1921: 2,048 logs

DS1922: 4096 or 8192 (depending on resolution)

DS1923: 2,048 or 4,096 (depending on resolution)

USB adaptor
Security ID Engraved unique serial number on the case. This number also embedded in internal electronics.
Resolution 1921: ±0.5 °C
1922: ±0.5 °C (low resolution) or ±0.0625 °C (high resolution)
1923: ±0.5 °C (low resolution) or ±0.0625 °C (high resolution)
Accuracy ±1 °C from -20 + 70 °C, at time of calibration at factory.
Time Accuracy Maximum 8 minutes per month over full temperature range.

Thermochron is a registered trademark of Maxim Integrated Products.

Thermochron and iButton are registered trademarks of Maxim Integrated Products.